What is the lower target rate if the upper target heart rate for a 45-year-old is given as 157.5 bpm?

To determine the lower target heart rate for a 45-year-old when the upper target heart rate is 157.5 bpm, we often use a method based on a percentage of the heart rate reserve or target heart rate zone, typically between 60% to 80% of the maximum heart rate.

First, we would need to calculate the maximum heart rate (HRmax) using the formula:

HRmax = 220 - age.

For a 45-year-old, this would be:

HRmax = 220 - 45 = 175 bpm.

Next, the target heart rate zone is often established between 50% to 85% of HRmax for moderate to vigorous intensity. Since the upper limit given is 157.5 bpm, we can backtrack to find the lower limit based on the percentage calculation.

If we determine that 157.5 bpm is approximately 90% of HRmax, then we can assert the lower target heart rate (often calculated at around 70-75% for effective moderate intensity).

Using this calculation, applying 80% of 175 bpm:

Lower Target Rate = 0.80 * 175 = 140 bpm.

However, this may suggest that higher intensity training or target